A plasma may be used to activate thin film deposition reactions, such as reactions used in plasma-assisted atomic layer deposition (ALD). In such processes, plasma uniformity may affect the deposition processes and/or the resulting film. Because it can be difficult to form a uniform plasma during processing if the size of the plasma is large (e.g., when the deposition substrate has a large surface area), it has been suggested that increasing the electrode size may help form uniform plasmas for larger substrates. However, increases in plasma current resulting from increases in the electrode surface area can lead to plasma breakdown, flickering, and extinction.